As fit as a fiddle ： to be very healthy and strong

E.g., my grandmother's 89, but she's as fit as a fiddle

      As fresh as a daisy ： to be full of energy and enthusiasm

After a good night's sleep I'll be as fresh as a daisy

Like death warmed up: to look/feel very ill

E.g. He shouldn't be working when he's so ill - he looks like death warmed up!

       Down in the mouth: to be sad

 E.g. Since her boyfriend left, she’s been very down in the mouth

        Under the weather: to be or feel ill

E.g. I'm feeling a bit under the weather - I think I've caught a cold.

       Got out of bed on the wrong side:  to be in a bad mood and to be easily annoyed all day

E.g. He’s so moody today. He must have got out of the wrong side of bed.

       In a bad way: to be ill, unhappy, or in a bad state

E.g. She was thin and tired-looking and generally in a bad way

       As right as rain: to be healthy, especially after having been ill for a period of time

E.g. Since he started taking the new medicine, he’s been as right as rain.

Off-color: slightly ill

E.g. I'm feeling a bit off-color today.

      Run-down: tired and not healthy, especially because of working too much

E.g., my doctor said I was looking run-down and ought to take some time to rest.